FTP not calculating correctly

I’ve tested my FTP using the 20 minute test several times, and always in the 238-241 range (Most recently based on 20min@252 under fairly ideal conditions). Xert estimates my FTP at 273. While flattering, it’s producing workout targets that I simply can’t hit. How to I permanently (or at least temporarily) correct my Xert FTP back to 241.

241W is well below your actual threshold power, at least the way it is measured in Xert. Unless you’re using multiple power meters with different calibrations, your Aug 9th effort would be impossible with a FTP of 241W. You averaged 224W, with most of that time spent going easy and with a tremendous sprint at the end meaning you had a lot left and could have gone much harder. This can’t be done with an FTP of 241W. That’s why Xert has given you a much higher value. Outside of data errors that may have caused the discrepancy, this is what you should be using.

Which targets are you trying to hit? Can you provide an example? (Use your Signature Calcualtor which shows your Power Curve to see how long you should be able to sustain various power values).

Armando, thank you for the reply. I’ll give it a try, but what do you recommend that I do on workouts where the, like “Seiler 4x16 Study Workout”, I’m supposed to hold 270 for 16 minutes four times. I down-tuned the workout to 240, and was still only able to hit 227-233.

Could it be something with the alogrythm needs to be tweaked for certain fitness-types. I’ve very good at endurance, but can’t manage higher power/speed. In running my 5k pace is about 6:!5, while for a marathon I can hold 6:48. Based on the 6:48 in the marathon, most people say I should be running my 5k much faster.

I would say that you’re more likely to be the opposite. You can produce higher power but might have difficulty on sustained efforts.

The Seiler workouts are very hard. Look at the difficulty rating for workouts and try initially to avoid the 3 stars and higher. Build up to those.

Good luck!